Singapore’s PUB starts construction on DTSS Phase 2 conveyor system

Singapore’s national water agency PUB has broken ground for the enhanced conveyance system of the Deep Tunnel Sewerage System (DTSS) Phase 2.

The latest development, which marks the start of construction works, took place at the site of DTSS Phase 2’s first tunnelling shaft at Penjuru Rd.

Linking to the existing tunnels in Phase 1, the deep tunnels in Phase 2 will serve the eastern part of Singapore and the public sewer network to create a single integrated system.

Upon completion by 2025, the DTSS Phase 2 will serve the whole of Singapore.

Three centralised water reclamation plants will receive used water from the DTSS through gravity for treatment, before it undergoes further purification to produce NEWater.

The 100km used water conveyance network for DTSS Phase 2 will be built using the tunnelling method and would run largely under the Ayer Rajah Expressway (AYE).

It will cross undersea at Tuas Bay and end at deep inlet shafts within the future Tuas Water Reclamation Plant.

PUB DTSS Phase 2 director Yong Wei Hin said: “The construction of the conveyance system for DTSS Phase 2 will pose a new set of exciting challenges for us, as we look forward to dig deep to navigate through a variety of ground conditions in the Jurong Formation as well as tunnel beneath existing underground infrastructure and even under the sea.”

Digging at depths of between 35m and 55m below ground and under the sea will be carried out using 19 tunnel boring machines to create 40km of deep tunnels and 10km of link sewers.

The remaining 50km of link sewers will be constructed with the help of a micro-tunnelling method known as pipe jacking.

The deep tunnels will be lined for corrosion protection and will use air jumpers in the operations of its air flow management system.